Saturday, August 29, 2009

Habitat and food mark out Sunderbans tigers

Habitat and food mark out Sunderbans tigers

Ananya DuttaAugust 21, 2009

Living in the inter-tidal habitat among marshy thickets, having become accustomed to the saline water, and but often without the trademark element of surprise, the Royal Bengal Tiger of the Sunderbans may have evolved differently from its brethren in peninsular India, according to experts here.

Forest Department Officials are constantly discovering aberrant behaviour patterns. The July 17 finding of poisonous snakes in a tiger’s stomach is one such example. “While tigers are known to eat snakes, this is perhaps the first record of a tiger eating poisonous ones,” said Richa Dwivedi, deputy field director of the Sunderbans Biosphere Reserve.

“Although it is yet to be confirmed scientifically that the tiger is genetically different from terrestrial tigers as the DNA analysis has not been done, there are certainly many physiological adaptations,” said Pradeep Vyas, the State Forest Department’s chief conservator of forests (Central).

There is strong evidence of the fact that tigers in the Sunderbans drink saline water, says N.C. Bahuguna, director, Sunderbans Biosphere Reserve.

“There are nearly 270 tigers in the Sunderbans, but the few fresh water ponds that were created are not sufficient to support this large a population,” said Pranabesh Sanyal, former director. “In any case, there were no fresh water ponds before 1977, so what else could the tigers drink then?”

These tigers have to negotiate harsh habitat conditions, apart from non-availability of fresh water. The muddy and marshy areas, dotted with pneumatophores (spiked roots of mangroves which abound in these forests), have forced them to hunt differently, says Mr. Vyas. “When they walk on the wet soil, it is often noisy and they can’t stealthily approach their prey, like tigers normally do.”

Aquatic diet

Difficulties faced in hunting may be the cause of their alternative food habits, although experts differ on the reasons. “Studies have shown that nearly 20 per cent of the diet of tigers in these parts is aquatic including fish, crabs and turtles,” said Mr. Sanyal, who suggested that easy availability of these substitutes might cause them to eat this food. At times, even grasshoppers have been found in the stomach contents of these tigers, according to Mr. Bahuguna.